1. Field of the Invention
The present invention relates to a sensor module, and more particularly, to an image sensor module.
2. Description of Related Art
The process for manufacturing CMOS image sensor (CIS) is compatible with that for manufacturing CMOS transistor. As this image sensor can be easily integrated with other peripheral circuits onto the same chip, the cost and power consumption of the image sensor are greatly reduced. In recent years, the CMOS image sensor has replaced the charge-coupled device (CCD) in the lower level application and has become popular day by day.
FIG. 1 is a schematic view of a conventional image sensor module. The conventional image sensor module 100 comprises a substrate 110, an image signal processor (ISP) 120, an image sensor chip (CIS) 130 and an actuator 140. The substrate 110 has a bottom surface 110a and a corresponding top surface 110b. The image signal processor 120 is disposed on the bottom surface 110a of the substrate 110 and electrically connected to the substrate 110. The image sensor chip 130 is disposed on the top surface 110b of the substrate 110 to capture image data, wherein the image sensor chip 130 is electrically connected to the substrate 110 via wire bonding. The actuator 140 is disposed on the top surface 110b of the substrate 110, and covers the CIS 130. The actuator 140 comprises a plurality of optical lenses 142 and accomplishes the operation of image self-focusing through the control of the image signal processor 120. A filter 144 is disposed below the optical lens 142 for filtering out unnecessary lights. The above image sensor module 100 is electrically connected to a flexible circuit substrate 10 and delivers image signals captured by the image sensor module 100 to a chip 12 on the flexible circuit substrate 10, so as to process the image signals.
However, the conventional image signal processor 120 is disposed on the bottom surface 110a of the substrate 110 in the form of a module, such that the whole image sensor module 100 has a larger thickness, which thus cannot satisfy the current requirements for the electronic products of being light, slim, short, small and portable.
Referring to FIG. 2, which shows a schematic view of another conventional image sensor module. In the image sensor module 200 shown in FIG. 2, an image signal processor 220 is disposed on a substrate 210, and is electrically connected to the substrate 210 by wires 260. An image sensor chip 230 is stacked on the image signal processor 220 via a spacer 250, and is electrically connected to the substrate 210 by wires 270. Being similar to the above image sensor module 100 shown in FIG. 1, the image sensor module 200 is electrically connected to a flexible circuit substrate 20, and delivers image signals captured by the image sensor module 200 to a chip 22 on the flexible circuit substrate 20, so as to process the image signals.
However, in the image sensor module 200, overheat of the image sensor chip 230 and the image signal processor 220 may easily occurs and lead to low working efficiency or short life time due to the stacked disposition between the image sensor chip 230 and the image signal processor 220. In addition, the internal height of the actuator 140 is generally considered only for accommodating the image sensor chip 230, and the height is restricted to some extent. When the actuator 140 is assembled on the substrate 210, the actuator 140 may easily squeeze and damage the wire 270 connected between the image signal processor 220 and the substrate 210, which may lead to the failure of electrical signal transmission between the image signal processor 220 and the substrate 210.